Control for vehicle brakes



Jan. 15, 1946.

CONTROL FOR VEHICLE BRAKES Original Filed Oct. 18, 1941 i iiiiillINVENTOR Carolus Likserqicm ATTORNEY c. L. EKSERGIAN 2393,31

3 Sheets-Sheet l Original Filed Oct. 1 8, 1941 3 Sheets-Sheet 2 PIC-7INVENTOR Carolus Likserqion BY ATTORNEY Jan. 15, 3946. c. L. EKSERGIANCONTROL FOR VEHICLE BRAKES 1941 3 Sheets-Sheet 5 Original Filed Oct. 18

INVENTOR Carolus LEkserqian By %%W ATTORNEY ,ing wheel, since it is trolincluding an inertia Patented Jan. 15, 1946 CONTROL FOR VEHICLE BRAKESCarolus L. Ekserglan, D

Budd Wheel Compan poration of Pennsylva Original application October415,518. Divided and this 1942, Serial No. 447,222

etroit, Mich, assignor to Philadelphia, Pa., a cornla 18, 1941, SerialNo. application June 16,

4 Claims. (Obits-181) The invention relates to a wheel protector forrailway wheels and particularly to such a device adapted to preventsliding of the wheels on the tracks due to brake application.

This application is a division of copending application Serial No.415,518, filed October 18, 1941, now Patent No. 2,365,180, issuedDecember 19, 1944.

In modern high speed trains, adequate braking becomes highly importantto enable the train to be brought to a stop within reasonable distances.It is of no avail, however, to exert power and if the braking force isnot reduced it will rapidly decelerate to a "locked state in which itslides on the rail. Such sliding on the rail is objectionable for tworeasons; first, it wears "flats" on the slid wheel nece itating theremoval of the wheel and the grinding and truing thereof, and second,the sliding wheel has less retarding efiect on the train than a brakedrollefilcient of rolling friction.

It is an object of the invention to overcome these difilcul-ties andinsure that the braking force never, during running, is allowed toremain on long enough to permit a slipping wheel to reach the slidingstage, but to maintain the braking at a high efiiciency by promptl againapplying the braking force to the wheel as soon as may be after thewheel has returned to normal speed following slipping thereof.

It is further an object of my invention to provide an instrumentality ofthis class which is simple in construction, efilcient in operation,assured of along life in use, and one which can be readily applied tothe vehicle and manufactured at low cost.

In practice, the device may consist of a suitable valve mechanisminserted in the usual operator-controlled pressure line to the brakecylinder and an automatic control for the operation of said valve to outofi and release pressure to and from the brake cylinder, said congovemorresponsive to excessive acceleration and deceleration, such as takesplace on wheel slip, of the wheel being braked. Preferably, one suchcontrol device is ingovernor device of Figs. 1

. enlarged scale taken on the line With the usual axle having two wheelsfixed thereto, it is desirable to associate a control device with eachaxle.

Other and further objects and advantages and the manner in which theyare attained will become apparent from the following detaileddescription when read in connection with the drawings forming a part ofthis specification.

In the drawings:

Fig. 1 is a vertical axial sectional view through a preferred form ofinertia governor device shown applied to the end of a vehicle axle.

Fig. 2 is a section at right angles to the section of Fig. 1 taken. onthe line 2-2 of Fig. 1.

Fig. 3 is a fragmentary sectional view taken' on the line 3-3 of'Fig. 1.

Fig. 4 is a sectional View, the section being taken on the line t-d ofFig. 1.

Fig. 5 is a. fragmentary sectional View on an enlarged. scale taken onthe line 5-5 of Fig. 4.

Fig. 6 is a fragmentar sectional view on an t 6 of Fig. 1.

Fig. 7 is a fragmentary sectional view taken on the line 7-? of Fig. 2.

Fig. 8 is a diagrammatic view showing the electro-pneumatic system whichmay be controlled by the governor device of Figs. 1 to 7 or its.equivalent.

Fig. 9 is a similar modified system which diagrammatic view of a may becontrolled by the to 7 or its equivalent.

In the preferred form of inertia governor tievice of Figs. 1 to 7,inclusive, the inertia governor device together with the electric switchcontrolled thereby is housed in a unitary casing in which may take theplace of the of the axle bearing box it to the margin of the opening E2in a manner to form a. tight closure therefor, by the bolts 53.

The casing, ,for convenience of assembly and disassembly, may comprisetwo sections it and i5 forming a. tight joint with each other andsecured together by bolts 86. The rotary inertia member 51 is mountedthrough an antifraction bearing l8 upon an outwardl projecting boss l9extending from the inner wall it of the casing it. The outer race of thebearing It issecured to the hub of the inertia member between a,shoulder at the inner end of the hub and a split ring engaging a grooveadjacent the outer end, while the inner race is secured between ashoulder on the inner end Of the boss and anut 2t screwed onto itsscrew-threaded outer end. The inertia member H is arranged to be drivenfrom the axle 2! of the vehicle usual cover on the end and be secureddirectly through a connection which is readily engaged when the casingin is assembled, by axial movement, with the axle box II and axle 2i,and in order to enable the inertia member, at times, to overrun or lagbehind the axle, the driving connection includes resilient means.

To enable the resilient drive to be arranged at the outer face of theinertia member where it is readily accessible by removing the outersection l5 of the casing, a crank shaft 22 is passed through a boreextending concentric with the axle through the inner wall 19' of thecasing and the boss 19 projecting therefrom, this shaft being rotatablein bearing bushings as 23 arranged adjacent the opposite ends thereof.At its inner end the shaft has secured to it an arm 24 which isbifurcated to straddle a stud 25 secured in eccentric relation to theend of the axle. At its outer end it has secured to it, as by a pin 28,an arm 21 which is also bifurcated at its outer end and provided withaxially extending driving extensions 28 and 29 one on each of thefurcations and spaced apart some distance, see Fig. 2. The extensions 28and 29 straddle a pair of spaced leaf springs 30 and 3| arranged alongchords approximating the diameter and at equal distances from theopposite sides of the axis of the inertia member.

These springs are secured as by rivets at one of their adjacent ends toaxial extensions 32 and 33, respectively, of a bracket 34 bolted to theouter face of the inertia member. Adjacent their opposite free ends theyextend close to the adjacent faces of the driving extensions 28 and 29,respectively, and at these free ends they bear against axially extendingabutments 35 and 36, respectively, projecting from a bracket 31 boltedto the outer face of the inertia member H.

The springs are preferably placed under a .certain amount of initialtension and are held against the respective abutments 35 and 36 underthis initial tension. If desired, the initial tension of the springs 30and 3! may be augmented by a coil spring 38 arranged between their freeends and adding its tension to that of the springs 39 and 3! to holdthem against the abutments 35 and 35, respectively. As clearly appearsin Fig. 2 the brackets 34 and 31 and springs 38 and 3| are arranged inbalanced relation about the axis of the inertia member so as to maintainit in balance.

From the' foregoing, it will be seen that the inertia member isconstantly driven from the axle through a yielding drive, in onedirection of movement through one spring, as 30, and in the otherdirection of movement through the other spring 3|. At normal rates ofacceleration and deceleration, say not exceeding 5 miles per hour persecond, the tension of the springs is sufficient to maintain themagainst the abutments 35 and 35 and the drive is affected with verylittle deflection of the springs, since the engagement of the drivingextensions 28 and 29 with the springs is very close to the abutments.When the acceleration or deceleration of the axle risesabove the normal,say to miles per hour per second, the initial tension of the spring thendoing the driving and, if the additional coil spring 38 is used, thetension of this spring the spring is moved against a, fixed abutment 39projecting axially from bracket 31 between the springs 30 and 3|. Whensuch movement occurs a switch in an electric circuit may be closed andheld closed as long as such excessive acceleration or decelerationpersists. When the accelera ion also, is overcome and provided betweenthe or deceleration again reaches the normal rate. 1. e. the rate oftravel of the vehicle, the tension of the spring under compressionrestores the parts to the position shown in F18. 2.

The switch controlled by the inertia member may comprise a spaced pairof collector rings 48 and 4| mounted on a plug 42 of insulatingmaterial, which plug has its outer end rigidly mounted in the hub of aspider 43 supported from the wall of the outer casing section IS. Theinner reduced end of this plug extends between the springs 30 and 3|substantially in axial alignment with the axis of the inertia member andcarries the collector rings axially on the opposite sides of saidsprings, The collector rings are connected to binding posts 44 and 45which in turn are connected to wires in the circuit to be controlled bythe switch which wires may be extended through the wall of the casing toa usual form of attachment socket indicated at 45'. Opposite the rings40 and 4| eachof the springs 39 and 3| carries a bridging contact 45secured to the spring intermediate its ends, suitably insulatedtherefrom and carrying a pair of contact buttons,

one at each end thereof, but normally spacedfrom the rings. When, clueto abnormal acceleration or deceleration, one of the springs isdeflected to engage the stop abutment 39, the bridging member contactbuttons of said spring are brought into engagement with the collectorrings to close the switch, closed until the parts return to the positionof Fig. 2, following a return to normal acceleration or deceleration.

To permit examination of the switch and drive at any time, a removablecover '41 is provided to close the outer reduced end of the casing It.When the cover is removed, direct access is had to the binding posts andto the inside of the spider 43 through the openings between the spokesthereof. To perm't filling of the axle box with oil to the requiredlevel to oil the bearings of the axle, a charging port 48 may beprovided in the casing part l4, see Figs. 1, 2, '7, this port opening atits inner end into the bearing box II and at its outer end beingprovided with a screw thread to receive a closing plug, not shown. Thebottom of the outer end of this port is preferably arranged at the levelat which it is desired to hold the oil in the bearing box. By placingthis port in the casing, it is unnecessary to provide a separate fillerport in the axle box.

To prevent leakage of oil from the axle box into the casing ID asuitable packing, as 49, is shaft 22 and the boss l9. Even if thereshould be slight leakage of oil past the packing, it would be thrown outcentrifugally into an inwardly facing annular channel 59 having aninclined bottom and discharged through an opening 5| extending from thelowest portion of said channel to the periphery of the inertia member,from whence it would collect by gravity at the bottom of the casing.

To prevent undesired sur es of the inertia memher, a damper ispreferably associated therewith. Such damper may comprise an arm 52extendin at substantially right angles from the arm 21 and preferablyintegral therewith, this arm 52 having at its free end a socket arrangedat right angles to the flat outer face 53 of the inertia member andcarrying for telescoping movement with said socket a brake shoe 54carrying on its face engaging the face 53 a suitable friction material55'. The shoe is pressed into braking engageand the switch will be held.

'sponsive device described or its ment by a spring BI housed within thetelescoping parts of the arm and shoe.

The operation of the inertia controlled switch shown in Figs. 1 to 7.inclusive will now be described. While the axle is rotating, the inertiamember I1 is driven through the shaft 22 and one of the axiallyextending driving arms 28 or 20, engaging the spring 30 or 3| adjacentthereto, one or the other of these arms and their cooperating springsdoing the driving dependent upon the direction of rotation of the axle.While the wheels and axle are decelerating at a normal rate duringbraking, the initial tension of the springs 30 or M is suflicient toprevent relative rotary movement between the inertia member and theshaft 22 re ting at the speed of the axle sufllcient to overcome eitherof the springs and close the switch by engagement of the bridgingcontact carried by a spring with the collector rings d0, ti. Undesiredsurges of the inertia member are prevented by the damping brake 52 to55. If, however, a wheel begins to slip, the axle at once begins todecelerate very rapidly and almost immediately after the start ofslipping attains a deceleration, say double the normal deceleration. Theinertia member under this abnormal deceleration overcomes the springopposite the driving spring, overrunning the axle speed, and inovercoming the resistance of the spring, moving its associated bridgingcontact into contact with the collector rings to close the switch. Theswitch will be held closed until the deceleration again drops to a ratenear the normal rate, say below miles per hour per second, when thespring tension will return the parts to the position in Fig. 2 with theswitch open.

With the arrangement of switch members shown little wear of the switchcontacts results because they are in engagement only at intervals ofwheel slip. At the same time, during such intervals the contacts areengaged with the collector rings and wipe over them to maintain themclean and free from accumulation of dirt or rust. Thus they are alwaysmaintained in ood condition they engage only in case of wheel slipping.

In Fig. 8 is shown a diagram of an electropneumatic brake control systemwhich may be employed in conjunction with the inertia-reequivalent, forcontrolling the brakes associated with a wheel and axle for preventingwheel slide. In this diagram, the inertia-responsive switch isdesignated by 95, the brake cylinder by 96, the operatorcontrolled pipeline for supplying fluid under pressure to the brake cylinder, by 9? andthe automatically controlled valve device controlling the admission toand release of fluid from the brake cylinder by at. The condition ofthis valve is controlled by the control circuit or circuits responsiveto the inertia switch 95. The valve 93 may comprise turn leads to theexhaust port I08, and opening not withstanding the fact that.

I02, by a sprin and bearing at the port through the partition I09surrounding the valve stem one end against a collar I I0 thereon and atthe other end against the adjacent end wall of the valve casing. In thisposition communication is established between the operator-controlledsupply pipe through the pipe III connecting the valve chamber I00 to thebrake cylinder. While the valve is in this position, the brake cylinderpressure is thus under the control of the operator and can be varied atwill.

When the wheel braked by the pressure in the brake cylinder starts toslip the switch is closed immediately, since the wheel starts todecelerate rapidly as soon as slipping is instigated. This closes aprimary circuit from battery I I2 or other source of energy. throughlead 3,. fuse H6, lead II 5, magnet coil I07, lead I35, switch pointI38, bridging contact I39, switch contact I38, lead 837, magnet coilIlt, lead II'I, switch contacts. of switch 95, lead H8, fuse H9, andlead I20 back to the other side of the battery. The closing of thiscircuit immediately causes the armature I ii of a closing switch in arelay circuit to be moved to the left, Fig. 8, closing the relay circuitfor energizing the magnet valve ill? to operate the valve IM to itsother or lower position, in which it cuts oil the supply of fluidpressure to the brake cylinder and opens the brake cylinder to exhaust.This relay circuit comprises battery H2, lead H3, fuse Md, lead H5,magnet coil I91, lead I2I, switch point I22, bridging contact I 23,switch point lZd, lead I25, fuse H9, and lead Nd back to the other sideof the battery. densers as M5 and I65 may the switch terminals tominimize arcing.

As soon as the valve is operated to the lower position the pressuredrops rapidly in the brake cylinder releasing the brakes and allowingthe wheel to accelerate back to normal. To prevent opening of the relaycircuit at the time when the wheel ceases to decelerate and again startsto accelerate, at which time the inertia-responsive switch 35 in theprimary circuit is open, a time delay device is associated with therelay circuit to hold the switch I22, I23, I24 closed for apredetermined time period after the opening of the primary circuit. Whenthe wheel has started to accelerate during slipping, the inertia memberat a certain point in the acceleration lags behind the wheel and closesthe primary circuit again through the inertia-controlled switch 95 andholds it closed until the wheel acceleration has again come back tonormal rate corresponding to the deceleration rate of the train as awhole. Not until the relay circuit is allowed to be opened by the timedelay device (which is again actuated to its starting position upon thesecond closure of the primary circuit and held .in this position whilethe primary circuit is held closed, and is finally allowed to open therelay circuit only after the time for which it has been set has elapsedfollowing the opening of the primary circuit as the wheel returns to itsnormal rate) is the valve returned to the position shown in Fig, 8 andthe pressure again allowed to build up in the brake cylinder to applythe brakes.

In the diagram the time delay device is shown as comprising a dash-potI26, the piston I21 and rod I28 of which is connected to the armatureI2I'. The piston I2! is provided with a oneway valve I29 permitting thefluid in the dashpot to pass rapidly without hindrance from left toright of the piston when the coil H6 is energized, to substantiallyinstantly close the switch by a light spring ISI.

I22, I23. I24. motion connection with the piston rod I20 and is normallyheld against a shoulder IN on the rod This lost motion is provided toallow the piston I21 of the dash-pot to move to the right the requireddistance before the shoulder I30 strikes the contact member I23 andopens the switch. The piston may be returned by usual means, such as aspring, (not shown) and the rate of return of the piston I21 to theright is controlled by a by-pass I32 the orifice I33 of which can beadjusted by an adjustable tapered plug I 34.

while a specific dash-pot delay device has been described, it will beunderstood that other known types of delay action devices could be used.By setting the dash-pot device to delay the opening of the relay circuitfor a, period greater than the period during which the primary circuitis Open when the wheel goes from deceleration to acceleration duringslipping, which has been found to be a very short period, of the orderof a fourth of a second, ample time is assured, before the fullreapplication of thebrakes, to allow the wheel to return to normalspeed, and yet the time can be so controlled that substantially nobraking eillciency is lost except that lost during the short time 'inwhich the wheel, while slipping. is deceleratmg and again acceleratingback to normal, which has been found of the order of one second or evenless. If, after reapplication of the brakes following wheel slipping,the track conditions should be such as to reduce rail adhesion, thewheel may again reach a slipping condition and in such event, the cycleto bring it back to normal before it actually slides on the track wouldbe repeated. Of course, the operator could prevent such recurrence if heobserved the track conditions and reduced the pressure in the controlpipe 91.

Immediately upon the closing of the inertia switch when a wheelbegins'to slip both magnet coils I I5 and II" are energized, the one toprommly close the secondary or relay circuit and the other to operatethe valve IIM to out ofl. and release position. The stem I06 of thevalve opens the primary circuit at switch contacts I38, I38 immediatelyafter closing of the secondary circuit, so that in this instance thetime delay device will have to be adjusted for a period greater than thecombined time of the deceleration period during which the inertia switchis closed due to deceleration of the wheel incident to slip and theperiod said switch is open while the wheel is passing from decelerationto abnormal acceleration such as will again close the inertia switch byrelative reverse movement of the axle and inertia member. Thus thesecondary circuit will be opened a predetermined time after the wheelcomes back to speed to permit the reap plication of the brakes. In theform shown in Fig. 8 the time at which the brakes are again reappliedassuming the operator keeps his brake applying valve in the sameposition during wheel slip, is a short time, say or the order of afourth of a second after the return of the wheel to the speed of thetrain.

In Fig. 9 is shown another modification of. the control circuits whichwill now be described, similar parts being designated by like referencenumerals.

The form of the device shown in Fig. 9 is calculated to make it possibleto reapply the brakes immediately after the wheel has returned to speedand is thus perhaps more eihcient in not losing when a wheel begins toslip The switch member 12: has a lost any braking time except such as isnecessitated to prevent wheel slide. The circuits are the same as inFig. 8 except that a lead I is arranged in parallel with the part of theprimary circuit including the magnet coils H5 and IIlI. Thus anothercircuit is completed through the inertia switch comprising battery II2,lead H3, fuse ,-I I4, lead Iii, coil I01, lead I, inertia switch 85,lead H8, fuse H9 and lead I20 back to the other side of the battery.

. The operation of this modification is as follows: Immediately uponclosing of the inertia-switch both magnets in the one branch of theprimary circuit are energized as before to close the secondary ortime-controlled circuit and to move the valve to cut of! and releaseposition. This latter movement agaln results in the prompt opening ofthe one branch of the primary circuit including the coil I IE, but theother branch of the primary circuit including the lead I and coil III'Iis maintained closed until the wheel has substantially ceaseddecelerating. During this period the valve IN is held in releaseposition by the combined action of the one branch of the primary and thesecondary circuits. When the primary circuit is opened at the inertiaswitch 95 as the wheel ceases to decelerate and held open until thewheel is again accelerating back to normal, the secondary circuit byreason of its time-delayed opening, is holding the valve open.

. As soon as the acceleration is sufllcient to again close the inertiaswitch, the first branch of the primary circuit, being held open at theswitch I36, I38, I38, since the valve is held open at this time by thesecondary circuit, is ineffective but the second branch including lead Iis eflective to maintain the valve open until the wheel has acceleratedback to normal, when the inertia switch is opened, even if the secondarycircuit has been opened before the wheel has accelerated back to normal.Thus, according to the modification, the brakes are again appliedimmediately upon the return of the wheel to speed after slipping, and aminimum of braking time is lost due to wheel slippage.

What is claimed is:

1. In a brake control for vehicle wheels, a brake --to or from saidcylinder to-fapply or release the brakes, a valve device for cutting ohthe operator-' controlled fluid pressure and for releasing fluidpressure from the cylinder to release the brakes, said valve devicebeing normally biased to inoperative position, a magnet for operatingsaid valve device, when energized, to move it to operative positioncutting oil the operator's control and releasing the fluid pressure fromthe cylinder, a relay circuit, when closed, energizing said magnet,another circult, means for closing said relay circuit upon the closingof said other circuit, a rotary inertia device normally rotatable withthe wheel and operative upon excessive deceleration or acceleration ofthe wheel, such as occurs upon wheel slip, to close said other circuit,means for opening said other circuit immediately after the relay circuitis closed, and means associated with the relay circuit closing means fordelaying its opening after closure for a predetermined time, said delameans being conditioned by the closing of said other circuit duringslipping of the wheel to extend the time of opening of the relay circuitand the return of the brake control to the operator until the wheel hasfully returned to vehicle speed.

2. In a brake control for vehicle wheels, a brake cylinder for applyingthe brakes of a wheel, an operator-controlled pipe connected to saidbrake cylinder to supply or release fluid pressure to or from saidcylinder to apply orrelease the brakes, a valve device for cutting oifthe operator-comtrolled fluid pressure and for releasing fluid pressurefrom said cylinder to release the brakes, said valve device beingnormally biased to inoperative position, a magnet for operating saidvalve device, when energized, to operative position cutting oil theoperators control and releasing fluid pressure from the cylinder, arelay circuit, when closed,

energizing said magnet, another circuit, means for closing said relaycircuit upon the closing of said other circuit, a rotary inertia devicenormally rotatable with the wheel and operative upon excessivedeceleration or acceleration of the wheel, such as occurs upon wheelslip, to operate a switch to close said other circuit, means for openingsaid other circuit immediately after the closing of the relay circuitand maintaining it open while the valve is held in its operativeposition, means associatedv with the relay circuit closing means fordelaying its opening at least until the wheel is accelerating backtoward vehicle speed, and a third circuit including said magnet and theinertia-controlled switch for energizing said magnet continuously fromthe opening of said relay circuit and until the wheel has acceleratedback substantially to vehicle speed.

8. In a brake control for vehicle wheels, a brake cylinder for applyingbrakes to a wheel or wheels of a vehicle, operator-controlled means forsupplying or releasing fluid pressure to or from said cylinder to applyor release the brakes, means for cutting out the operator-controlledmeans and for dumping fluid pressure from the cylinder to ease off thebrakes, said cut-out and dumping 40 the speed of the vehicle.

means being normally biased to inoperative position, a solenoid formoving said last-named means to operative position, a relay circuit,when closed,

energizing said solenoid, another circuit, means for closing said relaycircuit upon the closing of said other circuit, a wheel-slip-controlledswitch associated with said wheel or wheels and operative upon excessivedeceleration or acceleration of an associated wheel, such as occurs onwheel slip. to close said other circuit, means other than said switchfor opening said other circuit immediately after said relay circuit isclosed, and means associated with said relay circuit closing means fordelaying its opening after closure for a predetermined time, said delaymeans being conditioned by the closing of said other circuit upondeceleration of an associated wheel during slipping there-, of to extendthe time of opening of the relay circuit and the return of the brakecontrol to the operator until the wheel has substantially fully returnedto vehicle speed.

4. In a brake control for vehicle wheels, a brake cylinder for applyingbrakes to a wheel or wheels of the vehicle, operator-controlled meanscomprising fluid pressure means for supplying or releasing fluidpressure to or from said cylinder to apply or release the brakes, avalve for dumping pressure from said cylinder, a solenoid for actuatingsaid valve to dump said pressure, and means operative upon wheel slipfor energizing said solenoid comprising a wheel-controlled circuitadapted to be closed upon excessive acceleration or deceleration of anassociated wheel, such as is incident to wheel slip, a relay circuit,when closed, energizing said solenoid, said relay circuit being adaptedto be closed by the closing of said wheelcontrolled circuit, means foropening said wheelcontrolled circuit immediamly after the closing ofsaid relay circuit, and means associated with said relay circuit fordelaying its opening after closure for a predetermined time sufiicientto allow the slipped wheel to return substantially to CAROLUS L.EKSERGIAN.

